//------------------------------------------------------------------------------
// <copyright file="XPathAxisIterator.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
// <owner current="true" primary="true">Microsoft</owner>
//------------------------------------------------------------------------------

namespace MS.Internal.Xml.XPath {
    using System;
    using System.Xml;
    using System.Xml.XPath;
    using System.Diagnostics;
    using System.Globalization;

    internal abstract class XPathAxisIterator: XPathNodeIterator {
        internal XPathNavigator nav;
        internal XPathNodeType type;
        internal string name;
        internal string uri;
        internal int    position;
        internal bool   matchSelf;
        internal bool   first = true;

        public XPathAxisIterator(XPathNavigator nav, bool matchSelf) {
            this.nav = nav;
            this.matchSelf = matchSelf;
        }

        public XPathAxisIterator(XPathNavigator nav, XPathNodeType type, bool matchSelf) : this(nav, matchSelf) {
            this.type = type;
        }

        public XPathAxisIterator(XPathNavigator nav, string name, string namespaceURI, bool matchSelf) : this(nav, matchSelf) {
            if (name == null) throw new ArgumentNullException("name");
            if (namespaceURI == null) throw new ArgumentNullException("namespaceURI");

            this.name      = name;
            this.uri       = namespaceURI;
        }

        public XPathAxisIterator(XPathAxisIterator it) {
            this.nav       = it.nav.Clone();
            this.type      = it.type;
            this.name      = it.name;
            this.uri       = it.uri;
            this.position  = it.position;
            this.matchSelf = it.matchSelf;
            this.first     = it.first;
        }

        public override XPathNavigator Current {
            get { return nav; }
        }

        public override int CurrentPosition {
            get { return position; }
        }

        // Nodetype Matching - Given nodetype matches the navigator's nodetype
        //Given nodetype is all . So it matches everything
        //Given nodetype is text - Matches text, WS, Significant WS
        protected virtual bool Matches {
            get { 
                if (name == null) {
                    return (
                        type == nav.NodeType      || 
                        type == XPathNodeType.All ||
                        type == XPathNodeType.Text && (
                            nav.NodeType == XPathNodeType.Whitespace ||
                            nav.NodeType == XPathNodeType.SignificantWhitespace
                        )
                    );
                } else {
                    return(
                        nav.NodeType == XPathNodeType.Element &&
                        (name.Length == 0 || name == nav.LocalName) &&
                        (uri == nav.NamespaceURI)
                    ); 
                }
            }
        }
    }    
}
